May 21, 2011 11:01 GMT  ·  By

The next major iteration of Firefox has reached an important milestone on the way to general availability, which is slated for next month.

The first Beta development milestone of Firefox 5 is now available for download. Early adopters can grab it immediately and start test driving the release.

This is the fully-fledged, official Firefox 5 Beta, a detail which I need to stress since Mozilla has also offered pre-Beta releases labeled in a similar manner, including a trial that was actually a re-branded Aurora Build.

Firefox 5 Beta is available for download this early after the release of Firefox 4.0 because Mozilla has switched to an accelerated development and release cycle for its open source browser.

Essentially, the open source browser vendor is striving to release major versions of Firefox some six weeks apart. Firefox 5 will be the first, followed by Firefox 6 and Firefox 7, all wrapped up and offered to end users by the end of 2011.

In this regard, the company also overhauled the development channels for Firefox, with new releases evolving from Nightly to Aurora, to Beta and then to Release.

“After five weeks of testing on the Firefox Aurora channel, the next version of Firefox is ready for the beta channel,” a Mozilla representative stated.

“This release includes the Firefox channel switcher, performance and stability enhancements and support for the new CSS Animations standard to allow developers build more amazing Web experiences.

“The new Firefox channel switcher lets users move between Firefox Aurora, Beta and Release channels to test features at various levels of development, quality and polish.”

Since new major Firefox versions will be delivered approximately once every six weeks, users should not expect the evolution of the browser to be as drastic as before, when comparing iterations.

Instead, Mozilla will deliver fewer features, enhancements, etc. but will do so at a much faster rate.

Here are the changes in Firefox 5 Beta:

“• added support for CSS animations

• added support for switching Firefox development channels

• the Do-Not-Track header preference has been moved to increase discoverability

• improved canvas, JavaScript, memory, and networking performance

•improved standards support for HTML5, XHR, MathML, SMIL, and canvas

•improved spell checking for some locales

• improved desktop environment integration for Linux users.”

Mozilla is hard at work to deliver Firefox 5 Final on June 21st, 2011.

Firefox 5 Beta for Windows is available for download here.

Firefox 5 Beta for Mac is available for download here.

Firefox 5 Beta for Linux is available for download here.